SPRING NUMBER 63 
occur. Hubbard (22) is also of the opinion that the orange aphid 
lives over winter as an adult on the orange trees. The males and 
winter eggs were not discovered and probably do not occur, at 
least in ordinary seasons. 
Parasites. Aphis gossypii has several parasites and preda- 
ceous enemies. It is severely infested by the internal parasite, 
Diaeretus rapae, which often prevents it from getting started in 
a locality. The lace-winged flies, Chrysopa oculata, and Hemero- 
bius sp., and several species of lady beetles and syrphus flies also 
prey upon this aphid. They are often seen on orange trees 
which are harboring the lice. The aphid is not susceptible to 
fungus diseases however. Attempts made to get two species of 
fungi to live on them in the greenhouse failed. Hntomophorus 
aphidis, which kills off Myzus persicae in large numbers, would 
not attack Aphis gossypii, nor would Acrostalagmus albus, a 
culture of which was received from Porto Rico growing on the 
cane aphid (Sipha flava). 
LACHNUS PINI L. 
Although not of any economic importance some studies were 
made of this large pine aphid since it was used in some of the 
experimental work. Like the two preceding species, these aphids 
lived on the pine trees throughout the winter and continued to 
produce their young viviparously. The pines not being deciduous 
a fresh supply of food was always available. The cold was never 
sufficiently acute to kill the adults as in the case of its northern 
congenors, and hence winter eggs were not a necessity. 
This aphid never occurs in large numbers probably due to the 
high percentage of parasitism. Its large size makes it an easy 
prey for hymenopterous parasites. However a few of them 
could usually be found on the small pines of the species Pinus 
taeda. They continued to live there all through the winter and 
produce their young alive. In the summer, however, they became 
very scarce and were difficult to find. 
Life History. No very complete experiments were conducted 
to work out the life history of the species, but a good line on the 
number of generations and rapidity of breeding was obtained 
from the experimental work which will be recorded in the next 
paper. The average time required for the young to become adult 
was nineteen days, or in other words, the number of generations 
will be determined at this rate. Several days often elapse be- 
tween the time of becoming adult and that of starting to repro- 
